Structure for enhancing a heat exchange rate of an electric radiator

ABSTRACT

A structure for enhancing a heat exchange rate of an electric radiator is especially used in the electric radiator which applies a mineral oil to transmit the heat, such that a higher heat exchange rate can be achieved at a circulation part of related oil leaf. 
     A relative distance between inner pipe walls of the oil loop is shortened, and a ratio of a long side to a short side of the loop is set to be greater than 6:1, which enables a flowing heat-transmission oil to easily break through a threshold Reynolds number to form a turbulent flow. On the other hand, heat-carrying particles of small specific heat are mixed into the oil body to improve the effect of heat transmission.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a structure for enhancing a heat exchange rate of an electric radiator, and more particularly to a structure which is used in an oil-leaf electric radiator to improve the heat exchange rate of oil leaves.

(b) Description of the Prior Art

As an oil-leaf electric radiator does not consume oxygen and is not provided with a high temperature of burning, it has been widely used. To resist an internal pressure, an oil-leaf loop of the conventional oil-leaf electric radiator is in a circular cross section to effectively disperse stress; therefore, it is not able to allow a heat transmission oil to quickly deliver heat energy, causing a temperature inductor to be unable to control an operation of a heater and allowing the heater to operate at an excessively high temperature. Accordingly, the internal pressure of machine will be increased, such that a casing will be burst out to form an oil leakage or a blow-up.

For the aforementioned oil loop of circular cross section, if it is desired to easily achieve a turbulent effect, a diameter of the loop should be decreased; therefore, under an equal pressure, a flow rate of the loop will be inevitably increased, which will decrease a time to exchange heat with an inner wall of pipe, thereby resulting in a reduced efficiency of heat exchange.

For the heat transmission oil to be used, usually a mineral oil will be used as a heat transmission medium. However, after a long time of usage, the oil quality will be degraded to lose an effect of heat transmission, and viscosity and degree of lubrication of the oil will be greatly reduced. Therefore, when a performance attenuation time is reached, the heat transmission oil should be replaced. According to a rough estimation of business data, there are at least three large corporations among vendors who produce the oil-leaf electric radiators, and each company produces over a million of the oil-leaf electric radiators every year. If each machine requires 1˜3 liters or more of the heat transmission oil, then a severe pollution will be resulted after recycling the oil. Furthermore, the recycled oil cannot be converted for other regeneration purposes. Therefore, an obvious disadvantage exists in an issue of environmental protection.

Referring to FIG. 1, the oil-leaf electric radiator 1 is primarily composed of a plurality of oil leaves 2 connected in parallel. The oil leaves 2 are penetrated through each other with upper and lower oil packages 21, 22, a side of the machine is provided with an adjusting switch 11, and an interior of the lower oil package 22 is installed with a heater 12.

A middle of breadth of the oil leaf 2 is formed with an oil pipe 3, and a circulation zone 28 is defined by the oil pipe 3 and the oil packages 21, 22. The circulation zone 28 is surrounded by a sealing line 24, and a periphery of the oil leaf 2 is sealed by an edging line 23.

Referring to FIG. 2, the oil leaf 2 and the heater 12 are serially connected, and the heat transmission oil is circulated along a circulation path L, wherein, after the transmission oil enters into the heater 12, it carries the heat energy and flows into the oil leaf 2 which absorbs the heat and releases temperature, and then after its temperature drops, the oil will flow back into the heater 12 to absorb the heat, thereby constituting a circulated heat-up operation.

Referring to FIG. 3, as a distance from a center point of the oil pipe 3 installed in the conventional oil leaf 2 to an outside of the oil pipe 3 is longer due to that its diameter has an equal curvature, it is not able to quickly form a complete heat exchange.

The oil pipe 3 is provided with the circular cross section, and after the heat transmission oil is heated, it flows into the oil pipe 3, wherein a flow rate of a part of the heat transmission oil 5 that is close to an axis part A1 is definitely larger than that of a peripheral part that is close to a radial part A2 of inner wall 311. Therefore, only the body of heat transmission oil 5 that is close to the radial part A2 at the periphery of a pipe wall 36 can form a heat exchange operation, whereas as there is a longer distance from the axis part A1 to an outer wall 312, and the flow rate of axis part A1 is higher than that of the radial part A2 such that it can flow quickly, heat energy stored in the axis part A1 cannot be effectively exchanged.

The oil pipe 3 is formed by assembling a front leaf 25 and a rear leaf 26 facing oppositely, a periphery of the oil leaf 2 is surrounded by the edging line 23, and a breadth edge 20 exists only for an auxiliary heat dissipation, with a primary object for enhancing a mechanical strength of an outer circumference to protect the oil pipe 3. In addition, an object of surrounding the periphery of oil pipe 3 with the sealing line 24 is to enhance a mechanical strength of pipe body formed by the oil pipe 3, so as to resist the internal pressure.

When the conventional electric radiator operates to a working temperature, its switch will form a periodic on-and-off operation. As shown in FIG. 4, when the temperature reaches to a certain working temperature, the temperature curve will clearly become a wave shape which is resulted indirectly from the on-and-off operation of the switch. Correspondingly, as the on-and-off operation in a higher frequency should be performed by the switch intermittently, it is easy to damage the switch or even the heater. The most important is that when the aforementioned heater is subjected to the periodic on-and-off operation in a normal condition, its parts are easily degraded and damaged, and as the complete heat exchange cannot be performed to a part of the heat transmission oil, when a part of the oil liquid returns to the heater, it will absorb the heat energy again to accumulate a large heat, which allows the oil quality to be overheated to cause the degradation; following that, a heat dissipation performance is reduced. In general, after three years of usage, the heat dissipation performance of heater will be clearly disabled and therefore it should be replaced, whereas the waste oil cannot be reused, thereby constituting a large burden to an ecosystem.

The aforementioned shortcomings are caused by that the circulation process is not able to effectively proceed with the heat exchange, and the heat dissipation rate is slow. On the other hand, as shown in FIG. 1, a temperature inductive switch 110 is located at a position of the adjusting switch 11 which is installed at an exterior of the electric radiator 1. The temperature inductive switch 110 is used to sense a room temperature at an ambient of the machine, and there is an apparent difference, normally above 20° C., between the temperature received by the inductive switch 110 and the temperature at a periphery of the heater 12. According to a configured condition of usage, if the inductive switch 110 senses a 95° C. of temperature, a warm temperature can be created indoors through a transmission by air. However, the working temperature of heater 12 will actually achieve 115° C., which enables a surface of the heater 12 to be coked from the high temperature. After the ordinary heater 12 is dismantled, it can be found that its surface is covered with an explicit coke layer which prohibits heat in the heater 12 from being quickly exchanged outward, thereby forming a vicious circle.

Moreover, according to a configured requirement, the operating limit of the inductive switch 110 is a room temperature plus 108° C. under a U.S. safety regulation of UL (Underwriters Laboratories), or a room temperature plus 85° C. under an IEC (International Electrotechnical Commission) regulation. However, the heater 12 is out of control due to that the aforementioned inductive switch 110 is not able to quickly receive an instruction, which causes the heater 12 to operate continuously, such that the heater 12 will definitely be subjected to the high temperature. Due to that the high temperature will correspondingly affect thermal swelling of the heat transmission oil, the internal pressure will achieve to as high as from 0.08 to 0.12 Mpa. On the other hand, when the inductive switch 110 is malfunctioning and the heater 12 is continuously performing the heat-up operation, large internal pressure will be accumulated due to that density of oil body is changed from overheating, and a burst problem will be initiated if the internal pressure exceeds 0.16 Mpa.

Considering a resistance to the high pressure, the conventional oil pipe 3 is designed to have a circular cross section. However, this design results in the aforementioned shortcomings.

When the heat transmission oil is operating under the excessively high temperature, a large scale of swelling will occur, which increases a distance between the oil molecules and reduces a total capacity of heat dissipating.

A vicious circle will occur by combing the aforementioned shortcomings. Therefore, there are users on the market who prefer to use a ceramic, an electro-thermal, or a carbon light pipe heater for household heating.

The conventional oil loop design also includes a rectangular or a prismatic cross section. However, for a design basis of length to width ratio, only a uniform distribution of oil loop is taken into consideration without accounting for that the viscosity of existing mineral oil can facilitate a condition of turbulent flow, which will reduce the heat exchange rate.

Concerning that a pipe body can provide for a fluid state of the oil body in the pipe, under a condition of low pressure and low flow, a streamline inside the pipe body will be in a laminar shape, and if an over-threshold Reynolds number is achieved, a turbulent flow will be formed.

Relating to a driving force for circulating the heat transmission oil, it is that after the heater increases temperature, an unequal specific weight of the oil is formed by a change of oil density from heating, so as to form a thermal rising effect to achieve the drive for circulating. However, the driving energy is very small, and the flow rate of oil will be very slow correspondingly, which is difficult to form the turbulent flow at the pipe wall. In addition, according to the definition of Reynolds number, which is a threshold condition that the flow in the oil pipe turns into the turbulent flow, that it is equal to fluid density multiplying by fluid velocity, multiplying by a relative distance between the pipe walls, and then dividing by a coefficient of viscosity; therefore if the relative distance between the pipe walls is larger, it is more difficult to reach the threshold Reynolds number to form the turbulent flow. To enable the pipe flow to easily turn into the turbulent flow, the relative distance between the pipe walls should be decreased. A method is to reduce a cross sectional area at a pipe opening; however, after decreasing the cross sectional area, the flow rate in the pipe will be increased at an equal pressure, such that a time to exchange heat will be lost, thereby greatly reducing the efficiency of heat exchange.

SUMMARY OF THE INVENTION

The primary object of present invention is to provide a structure for enhancing a heat exchange rate of an electric radiator, which enables a heat transmission oil to proceed with a near complete heat exchange to improve the heat exchange rate, which improves an oil leaf to facilitate a turbulent flow, and wherein the heat transmission oil is added with heat-carrying particles to increase an efficiency of heat dissipation. After combining the aforementioned factors, the heat exchange rate of electric radiator can be increased to a favorable situation.

Another object of the present invention is to use a kind of heat transmission oil having a specific heat which is smaller than that of a mineral oil, as a hot medium, thereby being able to exchange temperature at high speed and to resist an eco-problem.

To enable a further understanding of the said objectives and the technological methods of the invention herein, the brief description of the drawings below is followed by the detailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a conventional electric radiator.

FIG. 2 shows a schematic view of a working principle of a loop-type electric radiator.

FIG. 3 shows a top cutaway view of an oil pipe structure of a conventional electric radiator.

FIG. 4 shows a temperature vs. operating time diagram of a conventional electric radiator.

FIG. 5 shows a top cutaway view of an oil leaf of the present invention.

FIG. 6 shows a side view of a plurality of oil leaves of the present invention, after being aligned.

FIG. 7 shows a side cutaway view of an oil leaf loop of the present invention.

FIG. 8 shows a temperature vs. operating time diagram of the present invention.

FIG. 9 shows a pressure vs. temperature diagram of the present invention.

FIG. 10 shows a schematic view of another embodiment of an oil leaf loop of the present invention.

FIG. 11 shows a schematic view of an embodiment of a loop having a hole of half part of the present invention.

FIG. 12 shows a schematic view of another embodiment of a loop of the present invention.

FIG. 13 shows a schematic view of a second embodiment of a loop of the present invention.

FIG. 14 shows a schematic view of a third embodiment of a loop of the present invention.

FIG. 15 shows a schematic view of an embodiment of a loop with a concaved ridge at its long side of the present invention.

FIG. 16 shows a second schematic view of an embodiment of a loop with a concaved ridge at its long side of the present invention.

FIG. 17 shows a perspective view of an embodiment of an oil leaf with an auxiliary heat exchange operation at its breadth side of the present invention.

FIG. 18 shows a schematic view of the present invention containing heat-carrying particles.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 5, an oil leaf 2 is formed by assembling a front leaf 25 and a rear leaf 26 facing oppositely, and a middle of breadth is formed with a loop 30 which is constituted by a long side 31 with its corners being connected with a short side 32 to form a cross section of a rectangular hole 300. In addition, a ratio of the long side 31 to the short side 32 is preferably to be 6:1.

Between the neighboring loops 30 of oil leaf 2 is installed with a separation band 27, and a basic method for constituting the loop 30 is to assemble opposite half parts 33, 34 which are formed at the front and rear leaves 25, 25 respectively.

As the oil leaf structure 2 of present invention will not allow a heater to operate at an excessively high temperature to prevent from resulting in a high internal pressure, its material can be thinned, such that its weight can be reduced and it can be easily processed and punched; both of them are able to save a production cost.

As the cross section of loop 30 is in a configuration of rectangular hole 300, the breadth of long side 31 will be used primarily for exchanging the heat, and as a distance from an edge of long side 31 to a center point of the loop 30 is greatly reduced, the heat energy carried by the heat transmission oil 5 in the center can facilitate exchanging the heat with the long side 31. It is definitely that the short side 32 is also capable of proceeding with the heat exchange.

The ratio of side lines of the rectangular hole 300 of loop 30 is that the long side 31 takes 6, whereas the short side 32 takes 1. According to the ratio of about 6:1, the existing heat transmission oils which are commonly used are easy to create a viscous effect, thereby improving the heat exchange rate.

According to the aforementioned design of loop, the short side 32 is used to shorten a relative distance, D, between inner surfaces of the long side 31, which should be decreased in calculating the Reynolds number.

The Reynolds number is equal to fluid density, ρ, multiplying by fluid velocity, V, multiplying by an inner distance D, and then dividing by a coefficient of viscosity, μ. From the aforementioned definition of Reynolds number, it is known that when D is decreased, the threshold Reynolds number will be lower, which is easier to form a turbulent flow inside the pipe. Of course, the aforementioned formula can be applied equally to a pipe of circular cross section, wherein the fluid velocity is determined by a certain area and pressure. Therefore, the meaning of D is the relative distance between the pipe walls. It is also known from the formula that if the density ρ gets larger due to thermal effect, it will be slower to achieve the threshold Reynolds number. However, as the change of density is not large, this delay will not be explicit. In addition, the coefficient of viscosity μ is determined by the oil quality.

In the present invention, the short side 32 is used to shorten the inner distance of the long side 31, such that it will be easier to create the turbulent flow which is functioning in an interior of loop installed in the metallic oil leaf. As a back side of the loop is subjected to pressure, a forward vector of turbulent flow in a solid angle will be formed along a direction of movement of the oil body. If that direction is perpendicular to a part of shear stress which is resulted from the viscosity of pipe wall, an effect of moment of force will be formed, which will enable the oil body to acquire a vector pointing to the inner wall of loop, such that is can be collided with the inner wall for proceeding with the heat exchange. In addition, a pressure difference per unit point of position will be formed in sections of circulation path, due to a change of turbulent flow rate, and a punching effect will be obtained by the pressure difference. Energy obtained by the punching effect can be used to mix the oil molecules of different temperatures, such as the cold and hot molecules, thereby achieving a fast and uniform heat transmission and exchange.

According to testing results of the existing mineral oils which are used normally, the turbulent effect can be made explicit by using the ratio of long side to short side of being equal to or larger than 6:1. The given long and flat cross section provides for a flow of heat transmission oil at a certain pressure which is formed when the oil body is heated by the heater. Therefore, under a certain pressure value, a change of pressure can only form a change of punching effect at the turbulent positions and will not clearly affect an entire circulation rate.

Referring to FIG. 6, the oil leaves are distributed with the loops 30, and each oil leaf is provided with the upper and lower oil packages 21, 22 which are serially connected to constitute a transversal passage. An interior of the lower oil package 22 is installed with a heater 12 which heats up the heat transmission oil 5 in the lower oil package 22. Due to the thermal effect of material, the heated oil will float up toward the loop 30 and will be accumulated when it reaches the upper oil package 21. After that, it will be again subjected to high temperature and high pressure from below to move forward along a unidirectional circulation path. Finally, as shown in FIG. 2, the oil will reenter into the heater 12 to receive high temperature.

Referring to FIG. 7, the inner surfaces of long sides 31 of the loop 30 are opposite to each other with a shorter distance, therefore after the heat transmission oil 5 enters into the loop 30, the state of turbulent flow will be formed due to the viscous effect between the oil body and the inner pipe wall. The turbulent-flow state can allow the heat energy in the heat transmission oil 5 to be easier to completely exchange with the inner walls of long sides 31, thereby accelerating the heat exchange of oil leaves.

According to experimental results of present invention, a 20° C. of difference is obtained by measuring the working temperatures at the upper and lower oil packages 21, 22 (as shown in FIG. 6) respectively. The high temperature occurs at the upper oil package 21, and the low temperature occurs at the lower oil package 22. If the temperature of lower oil package 22 is 95° C., then the upper oil package 21 will have about 115° C. of working temperature. As the heat transmission oil 5 is flowing by inertia, its heat will quickly transmit upward, toward the position of upper oil package 21. Correspondingly, the working temperature of heater 21 can be maintained at 115° C. without having to operate at the excessively high temperature. On the other hand, if a same kind of mineral oil is used as the heat transmission oil, then the oil will not be degraded from operating at the excessively high temperature.

Referring to FIG. 8, when temperature rises to a certain working temperature, the working temperature manifests a very stable linear relationship. Correspondingly, the switch can form a state of constant open, which means that the heater 12 is in a constant open operation. On the contrary, as shown in FIG. 4, the switch is in a periodic on-and-off operation; therefore, in addition to that the heater is easy to be damaged from an electric current impact, as operation points between temperature drop and temperature rise are very close, a plurality of ignition currents will be formed for startup operations, which will relatively consume power and cause the switch to be easily damaged. Moreover, as the conventional oil is subjected to an intermittent heat-up, its flow rate is also up and down, which will largely deplete a kinetic energy of the oil from being cooled down. In an initial period of driving the heat, the heater requires some time to heat up, and within that time period, the oil which is attached to a surface of the heater is also degraded due to a long time of heat-up.

The present invention can completely eliminate the conventional shortcomings. According to the principle of inertia, if the heater is operating at a stable condition, the electric current required will be a constant, which results in a stable power. As the conventional electric radiator is provided with the periodic on-and-off operation, the temperature will also change between high and low. During a process of increasing temperature, a larger electric current is required, which will cause an apparent consumption of power. In addition, under a condition that an inertia of kinetic energy is lost in circulating, the oil which is affixed to the surface of heater will be difficult to float away, which will result in the degradation of oil quality, the coking on the surface of heater, and an extremely large loss of work. On the contrary, under a same room temperature, the present invention can be operated with a heater of smaller power, and can relatively save power.

Referring to FIG. 9, as the circulation rate of heat transmission oil of present invention is a constant, and from good responses in FIGS. 6 to 8, the internal working pressure can be maintained at about 0.05 Mpa. A measurement of temperature at the upper oil package using an ambient temperature as a working condition shows that the temperature can be more than 100° C. Based on that pressure of 0.05 Mpa is lower than one-third of a standard test pressure of 0.16 Mpa, it shows that the working pressure of present invention is very safe. In addition, the heat transmission oil is not affected by overheating, and a good heat transmission capability can be maintained. Correspondingly, the oil can be maintained at a good performance, and the material of oil leaf can be thinned to reduce the weight. Furthermore, the heater will not need high power as the conventional electric radiator does, to save power, due to that the temperature can be effectively transmitted without a heat loss.

Referring to FIG. 10, a single half part 33 can be used to constitute the loop 30 of the oil leaf 2. Contrary to a flat-plate-shape front leaf 25, the half part 33 forms a rectangular hole 300 in a U-shape.

Referring to FIG. 11, the short side of half part 33 can be in a slant direction, so as to form a loop 30 having a cross section of a trapezoidal hole 301.

Referring to FIG. 12, the loop 30 is assembled by two half parts 33, 34 facing oppositely, wherein the short side 32 can form a slant edge with its corners being connected to the long side 31, so as to form a loop 30 having a cross section of a long prismatic hole 302.

Referring to FIG. 13, corners of the short side 32 can be connected to the long side 31 following its arc line, so as to form a loop 30 having a cross section of a long elliptic hole 304.

Referring to FIG. 14, the short side 32 of loop 30 is oppositely connected following a parabolic curve, with the long side 31 being formed along the parabolic curve, so as to form a loop 30 having a cross section of a long eye-shape hole 304.

Referring to FIG. 15, the long side 31 of loop 30 can be provided with a concaved ridge 35 which can also form a longitudinal concaved surface.

Referring to FIG. 16, radial surfaces of the front and rear long sides 31 are longitudinally provided with concaved ridges 35 respectively, whereas the front and rear concaved ridges 35 are staggered.

Referring to FIG. 17, a circulation zone 28 is assumed to be at peripheries of the oil package 22 and the loop 30. To increase an auxiliary heat exchange operation, flow distribution regions 29 are added to an edge line of the circulation zone 28 and a periphery of the oil leaf 2. Therefore, in addition to circulating upward from the loop 30, the hot oil from the lower oil package 22 will pass through the flow distribution regions 29 inside the breadth edge 20, which enables the hot oil to be completely filled in the entire breadth of oil leaf 2, thereby improving a total heat exchange rate.

In the present invention, an outer surface of the oil leaf 2 is further provided with a far infrared transformation device 4 which can receive a heat wave of the oil leaf 2 and transform it into a specific far infrared ray to be emitted, wherein a layer of coating 41 having an element for far infrared transformation can be coated on an entire surface of the oil leaf 2, thereby achieving a total transformation.

For the aforementioned many kinds of loops 30, to increase the turbulent-flow state, an inner wall surface of the loop 30 can be made into a rough surface, which will result in a change of multiple angles to a vector of passage of the flowing oil body. According to a change of reflection angle, the oil movement vector will be changed, whereas a chance to be in contact with the walls, and the turbulent flow formed in the process of reflection, will be increased. An interaction of cold and hot oil molecules can result in an interchange of mechanical energy, thereby improving an exchange rate of oil heat with the pipe walls.

Referring to FIG. 18, an interior of the body of heat transmission oil can contain heat-carrying particles 6, provided that a semi-floating status can be formed subjected to a loading of the heat transmission oil. Therefore, when the heat transmission oil 5 is flowing, the heat-carrying particles 6 can be driven correspondingly, and are very likely to be in contact with an inner surface of the loop 30 through the viscous and mixing effect between the heat transmission oil 5 and the inner walls of loop 30. The heat-carrying particle 6 is an element of lower specific heat, and is able to quickly absorb the heat energy to compensate the heat transmission oil 5.

The heat-carrying particle 6 is the element of lower specific heat, wherein if a metallic grain or a metallic oxide is used to form a grain of diameter in a scale of nanometer, then a contact area and specific weight of the particle 6 can be enlarged with a nanotechnology; therefore the specific weight of heat transmission 5 can be accepted and its loading can be sustained with.

The present invention further takes into consideration a problem of environmental pollution caused by the degradation of heat transmission oil due to a long time of operation, and emphasizes on using a clean hot medium as a substitute, provided that a mobility should be at least equal to or higher than that of the conventional heat transmission oil, and that its specific heat and viscosity should be accounted for. By adding fresh water into a water soluble anti-freezer, such as ethylene glycol, a phase-change point of the fresh water can be altered. A general person may think that the boiling point of a water solution is 100° C., however it will be too low to be used if applied to the electric radiator (for the international standard, UL, it is required to be less than or equal to 130° C.; whereas for IEC, it is required to be less than or equal to 110° C.), and the pressure of water solution will rise rapidly after vaporizing to exceed the standard of pressure vessel (the standard of pressure vessel is less than or equal to 0.16 Mpa) to result in a danger. Accordingly, the water solution is abandoned.

Actually, in a closed space of electric radiator, pressure will only change the boiling point of water solution, and it will not be the original 100° C. Therefore, by using this characteristic, as long as the pressure is controlled to be within the standard of pressure vessel, the problem of insufficient temperature can be solved. In other words, the heat transmission oil is designed to increase the temperature, so as to satisfy the requirement, while it is operating at a certain pressure. The present invention uses the nanotechnology to increase the temperature at a uniform speed, thereby solving this issue.

A condensing point of ordinary fresh water is 0° C., the water will be frozen at a temperature below 0° C., and the fresh water will change to a vapor state at the boiling point. Therefore, if ethylene glycol is added, the temperature range of liquid phase can be extended to below 0° C., thereby explicitly expanding the temperature range of phase change. After adding the aforementioned mixture into the fresh water, the condensing point can be adjusted to between −15 to 50° C.; therefore, it will be applied to a range of coldest air temperature in a commonly inhabitable area.

The hot medium formed by the fresh water assisted with the characteristics of ethylene glycol, in association with a good mobility of the fresh water, can be driven in the oil-leaf loop with a loading of low pressure. As the specific heat of water is larger than that of ordinary material, its exothermic rate is slower after absorbing the heat. Therefore, the water liquid at an end section of circulation path (such as at a top end of the oil leaf) can also carry usable heat energy, and is able to effectively exchange the heat at that position. Accordingly, both an upper part and a lower part of the oil leaf can uniformly release the hot temperature, and as the density of this kind of heat transmission oil is larger than that of the ordinary mineral oil, the heat energy that is absorbed and carried is greatly increased, correspondingly.

For the aforementioned facts that the range of phase-change temperature of water soluble hot medium can be expanded, and that the boiling point can be increased by adjusting the internal pressure of oil leaf, a test has been conducted. The result shows that under a safe pressure, the operating boiling point can reach 198° C. However, under a practical requirement that the operating temperature should be in compliance with the heat transmission rate of machine, the temperature of water soluble hot medium can be far below 198° C., which correspondingly maintains a safe liquid-phase state.

Furthermore, by using the fact that the fluid of water liquid is provided with a fast flow rate, the heat that is possibly accumulated on the surface of heater can be removed quickly, to avoid a cavity phenomenon that will cause a corrosion to the surface of heater or result in a blow-up of the heater, which will correspondingly prevent from creating the unnecessary internal pressure.

It is known that a pure ethylene glycol is an element without a toxicity, a color and a smell, which is not easy to vaporize, which contains a very small amount of chloride, sulfate, or heavy metal, and which will not cause any impact to a human and his or her skin surface (other than eating by a mistake). The half life of ethylene glycol is about 24 to 50 hours, and hence its chemical properties can be changed by placing still after being recycled. The pure ethylene glycol is a viscous liquid; however, its hydrophilia property is very good. Therefore, it is easy to be mixed into the fresh water, to reduce the condensing temperature of the water and to increase the vaporization temperature of the water. Accordingly, when it is used in a medium which is circulated in the electric radiator, a fast mobility, a good heat transmission capacity, and an eco-function can be available.

The ratio of ethylene glycol to fresh water in the aforementioned mixture is about 5:5 to 7:3.

To enhance a heat transmission capability of the aforementioned heat transmission liquid, heat-transmission metallic grains can be added into the liquid. The heat-transmission metallic grains can be the particles of metal after being highly disintegrated, or the powders of metallic oxide. Because the specific heat of metal is about a few times that of the fresh water, the heat dissipation rate in the heater can be greatly improved. As the operation of these metallic heat-carrying particles has been shown in FIG. 18, it will not be described again.

It is of course to be understood that the embodiments described herein is merely illustrative of the principles of the invention and that a wide variety of modifications thereto may be effected by persons skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims. 

1. A structure for enhancing a heat exchange rate of an electric radiator, used in an oil-leaf electric radiator to improve a heat exchange rate of the oil leaves, comprising an oil leaf, and a longitudinal breadth of which is provided with at least one loop; a circulation zone being defined inward by a periphery of the loop, and an upper and lower end of the loop being connected with oil packages which are penetrated with a heater, so as to form a circulation path for a heat transmission oil; a cross section of the loop installed in the oil leaf being constituted by a long side and a short side to form the loop with a rectangular hole, the long side being parallel to the breadth of oil leaf, and a ratio of the long side to the short side preferring to be 6:1.
 2. The structure for enhancing a heat exchange rate of an electric radiator according to claim 1, wherein more than two loops are arranged in parallel, and the circulation zone is formed by assembling with the upper and lower oil packages.
 3. The structure for enhancing a heat exchange rate of an electric radiator according to claim 1, wherein a flow distribution area is located from an outside of the circulation zone to an interior of edging line at a periphery of the oil leaf.
 4. The structure for enhancing a heat exchange rate of an electric radiator according to claim 2, wherein a flow distribution area is located from an outside of the circulation zone to an interior of edging line at a periphery of the oil leaf.
 5. The structure for enhancing a heat exchange rate of an electric radiator according to claim 1, wherein the loop is made by assembling two opposite half parts.
 6. The structure for enhancing a heat exchange rate of an electric radiator according to claim 1, wherein the loop is made by a half part affixed with a front leaf in a shape of flat plate.
 7. The structure for enhancing a heat exchange rate of an electric radiator according to claim 6, wherein the half part is a trapezoidal hole.
 8. The structure for enhancing a heat exchange rate of an electric radiator according to claim 5, wherein corners of the short side of loop are connected with the long side in a straight angle.
 9. The structure for enhancing a heat exchange rate of an electric radiator according to claim 6, wherein corners of the short side of loop are connected with the long side in a straight angle.
 10. The structure for enhancing a heat exchange rate of an electric radiator according to claim 5, wherein corners of the short side of loop are connected with the long side in a slant angle.
 11. The structure for enhancing a heat exchange rate of an electric radiator according to claim 6, wherein corners of the short side of loop are connected with the long side in a slant angle.
 12. The structure for enhancing a heat exchange rate of an electric radiator according to claim 5, wherein corners of the short side of loop are connected with the long side along an arc line.
 13. The structure for enhancing a heat exchange rate of an electric radiator according to claim 6, wherein corners of the short side of loop are connected with the long side along an arc line.
 14. The structure for enhancing a heat exchange rate of an electric radiator according to claim 12, wherein the cross section of loop which is made by connecting the long side along the arc line with the short side is a long elliptic hole.
 15. The structure for enhancing a heat exchange rate of an electric radiator according to claim 13, wherein the cross section of loop which is made by connecting the long side along the arc line with the short side is a long elliptic hole.
 16. The structure for enhancing a heat exchange rate of an electric radiator according to claim 12, wherein the cross section of loop which is made by connecting the long side along the arc line with short side is a long eye-shape hole.
 17. The structure for enhancing a heat exchange rate of an electric radiator according to claim 13, wherein the cross section of loop which is made by connecting the long side along the arc line with short side is a long eye-shape hole.
 18. The structure for enhancing a heat exchange rate of an electric radiator according to claim 5, wherein a breadth of long side of loop is concaved with an enhancing ridge.
 19. The structure for enhancing a heat exchange rate of an electric radiator according to claim 6, wherein a breadth of long side of loop is concaved with an enhancing ridge.
 20. The structure for enhancing a heat exchange rate of an electric radiator according to claim 18, wherein the enhancing ridges at a front and a rear side are staggered.
 21. The structure for enhancing a heat exchange rate of an electric radiator according to claim 19, wherein the enhancing ridges at a front and a rear side are staggered.
 22. The structure for enhancing a heat exchange rate of an electric radiator according to claim 1, wherein the oil leaf is made by punching a plastic metal plate.
 23. The structure for enhancing a heat exchange rate of an electric radiator according to claim 1, wherein an outer surface of the oil leaf is provided with a far infrared transformation device.
 24. The structure for enhancing a heat exchange rate of an electric radiator according to claim 23, wherein the transformation device is formed by covering on a surface of the oil leaf with a layer of coating which is able to transform the far infrared rays.
 25. The structure for enhancing a heat exchange rate of an electric radiator according to claim 1, wherein an interior of the loop is formed with a rough surface.
 26. A structure for enhancing a heat exchange rate of an electric radiator, used in a loop-type electric radiator within which a heat transmission medium is flowing, to improve an effect of heat transmission, comprising a mineral oil of high vaporization point; an interior of the aforementioned heat transmission oil containing heat-carrying particles which is driven by the oil body.
 27. The structure for enhancing a heat exchange rate of an electric radiator according to claim 26, wherein the heat-carrying particle is a metallic grain.
 28. The structure for enhancing a heat exchange rate of an electric radiator according to claim 26, wherein the heat-carrying particle is a metallic oxide.
 29. A structure for enhancing a heat exchange rate of an electric radiator, used in an electric radiator within which a heat transmission medium is flowing, and being provided with a high efficiency of heat transmission and an eco-function, comprising a liquid of low condensing point and high vaporization point as a hot medium which is formed by mixing fresh water with ethylene glycol according to a ratio of about 5:5 to 7:3.
 30. The structure for enhancing a heat exchange rate of an electric radiator according to claim 29, wherein an interior of the hot medium is added with the heat-carrying particles made by the metallic grains.
 31. The structure for enhancing a heat exchange rate of an electric radiator according to claim 29, wherein an interior of the hot medium is mixed with the heat-carrying particles made by the metallic oxide. 